iommu/tegra: smmu: Change SMMU's dependency on ARCH_TEGRA

Theoretically TEGRA_IOMMU_SMMU depends on ARCH_TEGRA_3x_SOC and
ARCH_TEGRA_114_SOC only. This patch allows a Tegra20 only kernel to
enable SMMU(Tegra20 doesn't have a SMMU), which could avoid editing
this Kconfig entry every time we add a new chip later.
Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

drivers/iommu/Kconfig

@@ -158,7 +158,7 @@ config TEGRA_IOMMU_GART
 
 config TEGRA_IOMMU_SMMU
 	bool "Tegra SMMU IOMMU Support"
-	depends on ARCH_TEGRA_3x_SOC && TEGRA_AHB
+	depends on ARCH_TEGRA && TEGRA_AHB
 	select IOMMU_API
 	help
 	  Enables support for remapping discontiguous physical memory